iZotope BreakTweaker reviewed

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For the life of me, I couldn’t figure out how he did it. I’d listen over and over, trying to program those incredible sonic edits that electronic music legend BT is known for. His plug-in Stutter Edit (reviewed Aug. ’11) finally let us do some of these tricks, but BT has hinted for years of a follow-up plug-in for rhythm creation. Enter BreakTweaker. Fundamentally it’s a “groovebox” plug-in, but that’s kind of like calling a Porsche Panamera plug-in hybrid a “gas-saver.” Everything isn’t all roses, but what BreakTweaker does well, nothing else can do at all.

PROS: Unprecedented tools for integrating complex time-based micro-edits into electronic grooves and beats.Powerful step sequence-based drum machine. Powerful sample-based and DSP synthesis engines. Interface mostly makes dealing with all this complexity very easy. Huge 2GB sample library, with much content created by electronic composer BT.

CONS: No Swing parameter. Only 75% of the pattern window’s width is visible at any given time. DSP synth engine produces aliasing. Skimpy number of pattern and Generator presets. Can be CPU-intensive.

Bottom Line: A groundbreaking integration of groove machine and glitch/stutter generator that no EDM artist or music-for-picture composer will want to go without—but with a few “version 1” speed bumps.

Standard: $249 street | Expanded: $299 street | izotope.com


Six percussion tracks are available for groove creation, each with its own solo and mute button (see Figure 1 above). Next is a Waveform Edit button for each track, which opens the Generator window. A Generator preset is the closest thing here to a “patch”—more on this in a bit. A Play button triangle triggers each track’s sound, and if you click on the folder icon, it opens the Generator presets menu, so you can call up a different sound. Next is the playback multiplier, which alters the track’s playback speed from 1/3X to 3X.

Up next are the track volume and pan knob and the 32-step step sequencer grid. Timing events on the grid are light blue: click to create and double-click to remove. You can change their length by dragging the right edge, and their volume by dragging up or down. Under the 32 steps is a solid bar; changing its length makes that track longer or shorter. All this is per track, which allows complex groove possibilities before you even get into the MicroEdit window, which operates per event, and is by far the coolest feature in BreakTweaker.

One odd design choice is that the main interface doesn’t show you all of the overall drum pattern. There’s a window box at the top that’s visually reminiscent of Pro Tools’ “universe view,” and you have to drag it left or right to see the first two or final two beats of a two-bar pattern. Either you get used to jockeying back and forth or you make your patterns one bar long—which, interestingly, is the default length for new patterns.

Micro Editing

BreakTweaker’s sequencer is unique because each event can be a different length, and the way any event behaves depends on the MicroEdit window. You could divide a single timing event so that it triggers itself more than a thousand times. With the innovative Type, Slope, and Gate parameters, you can create mind-blowing stutter, glitch, and timing effects. The Type can be set to divide the timing events by an absolute number of divisions, a set timing value, a starting pitch, or an absolute speed in Hz. The Slope parameters decide how evenly these divisions are distributed over time: “Tension” controls whether they play in an accelerating or decelerating manner (from subtle to extreme) and “Rotate” alters the playback “phase” of the micro-edited events. Gate sets the gap between events. You get 34 Slope presets, which affect how all these settings interact.

You can transpose the pitch per event, add a distortion or filter effect per event, and the fade-in/out volume parameter is very useful. At far right of the Sequencer window is an output assignment setting for each track; this is helpful because there are no mastering, delay, or reverb effects built in.

Though there’s no swing or shuffle parameter (a glaring omission to some, but perhaps not to makers of four-on-the-floor dance music), I found a way to make parts kind of swing: Drag an event width to a quarter-note, with a division of 2, and use the “Kinda Slope” preset.

Sound Engine

A BreakTweaker sound is called a Generator (see Figure 2 at left). Each of the six tracks is assigned one Generator, which in turn can consist of up to three Generator Lanes—think of Lanes as layers. Each Lane can use either a sample-based sound or a two-oscillator synth, so you can mix and match. Clicking the waveform display opens the Generator editor, which is laid out in three sections: Oscillator; Distortion, Filter, and Mix; and Modulation, which contains four envelopes and four LFOs. For sample-based Lanes, you can optionally drag-and-drop samples from your computer.

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Fig. 2. In the Generator Edit view, you can create and edit sounds based on samples or an internal synth engine. With the current track across the top and MicroEdit across the bottom, you see everything pertinent to the sound of one track.

 As to factory sound choices, each drum type is divided into sub-folders. For example, the Kick folder has sub-folders named Acoustic, Basics, Dubstep, Electro, Hip Hop, Minimal, Trance, and Vintage. You might want to try the Discovery button, which uses a cloud-based audio search engine. (Internet connection required, and it only works with the factory samples.) Looping with realtime crossfades is available for fleshing out samples that need to play longer than their original length.

The other option is the DSP synth, which shows you a waveform display with two tabs at the top to select between oscillators 1 and 2. Here, a folder icon lets you peruse 99 different wavetable presets, ranging from basic waveforms for subtractive synthesis to complex multi-wave tables. The Distortion section can produce two distinct distortion presets at the same time. Distortion flavors include Warm, Transistor, Hard, Digital, RAW, and Aliasing. There’s a mix parameter, but be aware that some of the distortion presets alter the sound even when mix is set at zero.

Next up is a single Filter that with three sonic characters: New York, Tokyo, and Brick Wall. All include lowpass and highpass options; New York adds a bandpass mode. A mix stage lets you change panning and volume for the current Lane. The ADSR envelopes feature adjustable curvatures for the attack, decay, and release segments.

The LFO offers more than 80 waveforms. LFOs can sync to host, and retrigger (or not), and you can shift the phase. When you combine these LFOs with the complex wavetables and synthesis abilities, some pretty dynamic sounds can be produced on a single track. Virtually every knob or slider can have two modulation sources, but be aware that the envelopes and LFOs are the only sources available.

BreakTweaker’s synth engine produces noticeable aliasing. It’s not just on very high notes; playing a simple sawtooth wave C4, I could both hear it and see it on a spectrum analyzer relative to another soft synth, Reveal Sound Spire (see Figure 3 below). Since BreakTweaker designed for making in-your-face beats and grooves with an EDM focus, maybe this is less of an issue than it would be for most synths. Still, reducing the aliasing would make the synth engine’s powers more clearly heard, and iZotope is looking to improve matters in an update.

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Fig 3. Side-by-side comparison of playing middle C with the default sawtooth waveform from Spire (left) and BreakTweaker (right). Because of the aliasing it produces, the synthesis capabilities of BreakTweaker are not as sonically impressive as they could be. Click image to enlarge.

Sound Library

BreakTweaker’s library is divided into Pattern and Generator presets. A Pattern preset contains up to six tracks and typically 12 patterns (out of a possible 24) in a number of electronica genres. The Generator presets come in drum, synth, and bass flavors. Although there are many acoustic drum and some percussion samples, the factory patterns and sounds are focused strictly on modern dance styles. Having only 69 Generator presets seems skimpy given that there are over 4,000 samples. To get the most out of BreakTweaker, you have to dig deeper into the Generator editor. Three additional libraries come in the expanded version. Cinematic Textures is a must for composers, with more than 700 sound design-focused samples and 71 incredible patterns. Vintage Machines is very useful but is really more pop/dance than vintage. The Kick and Snare expansion, however, doesn’t have a single Pattern or Generator preset to support its 102 samples.

In Use

Despite its under-the-hood complexity, BreakTweaker is almost primitively simple to use. On a MIDI keyboard, you play chromatically from C1 to play the six sounds assigned to each track. Play chromatically from C2 to trigger the 24 separate patterns. There are two play modes: Gate and Latch. Gate starts with a note-on and stops with a note-off. Latch starts when you hit a key (or drum pad) and doesn’t stop until you hit it again, freeing your fingers to change patterns. With the “Always Retrigger” toggle turned turned off, you can trigger new patterns and they won’t restart the whole thing from beat 1, which is very useful for sequencing realistic and dynamic rhythms. Though there are no realtime MIDI parameters to map physical controls to anything inside the engine, every parameter (for all six tracks) is registered in the automation list of your DAW.

To make your own patterns, it’s fun to click in the grid and get a cool groove going. Select “Load Kit Only” from the main preset directory to load samples and get started even faster. You also can select one of the 24 pattern boxes in an existing pattern to further develop one of the factory patterns. However, there are a few things that I hope iZotope will change in a future update. As of version 1.0, all patterns have to share the same Time Multiply and Track Length settings. These are terribly limiting. For example, if you make a half-note hi-hat groove for pattern 1, the hi-hat track will be a half-note in length for the other 23 patterns. You can’t have a multi-time-signature polyrhythmic breakdown in the middle of your song, because if you try, all 24 patterns will be multi-meter polyrhythmic. Also, volume and pan are not stored on a per-pattern or per-micro-edit level. It would be nice to change these settings throughout a song.

As to CPU use, my 2010 six-core 3.5Ghz Mac Pro kept chugging along without any issues. However, my 2006 quad-core 3.0Hz Mac Pro had problems playing even three tracks without audio dropouts. I highly suggest downloading the demo version to see how it works with your computer.


If you want to experiment with complex rhythms and incredible stutter edits, BreakTweaker is a no-brainer. The sonic quality of the extensive sample library is also a big plus. These world-class sounds and the unprecedented timing engine earn a major thumbs-up. However, the lack of swing, the truncated view of the pattern window, and the relatively small number of Generator presets make BreakTweaker seem underdeveloped for a premium-priced software instrument. That said, the importance and coolness of what it does can’t be understated: It makes glitch, stutter, and complex micro-timing tricks a part of your initial beat-making process, whereas until now these had been effects or edits you had to apply after the fact. Nothing else does this.